Active substances


Chemical name

5- (3,4,5-trimethoxyphenyl) methyl-2,4-pyrimidinediamine

Chemical properties

Trimethoprim is an antibiotic that acts bacteriostatically. Most often it is used as a prophylactic for the treatment of diseases of the urinary system. The medicine is on the WHO list of essential substances.

The substance is synthesized in the form of a white crystalline powder. The product is odorless and tasteless, insoluble in water, poorly soluble in alcohol. The molecular weight of the compound = 290, 3 grams per mole.

The tool reached its greatest popularity by the end of the 70s of the 20th century, when it turned out that other antibacterial agents have a toxic effect on the bone marrow.

Pharmachologic effect

Bacteriostatic, antibacterial.

Pharmacodynamics and pharmacokinetics

The substance inhibits the activity of the enzyme folate reductasesand prevents education processes tetrahydrofolate.

The drug is active against gram positive and gram-negative microorganisms.

After oral administration, it is quickly and almost completely absorbed. The maximum concentration is observed after 60-180 minutes. Large concentrations of this compound can be found in the urinary tract and lung tissues.

The medicine undergoes a metabolic reaction in the liver. The substance is excreted in the urine through the kidneys.

Indications for use

Trimethoprim is prescribed for the treatment and prevention of bacterial infections of the urinary tract, which are caused by microorganisms sensitive to the action of the drug.


Drugs based on this substance should not be prescribed:

  • with serious violations in the work of the kidneys and liver;
  • deficient patients folic acid in the body;
  • pregnant women
  • at megaloblastic anemiadue to folic acid deficiency;
  • during lactation;
  • at allergies on the active component of the drug.

Side effects

Trimethoprim is generally well tolerated by patients.

Sometimes a medicine can cause:

  • nausea, headache, aseptic meningitis;
  • skin rashes, Stevens-Johnson syndrome;
  • nephropathy;
  • agranulocytosis, leukopenia, methemoglobinemia, anemia, thrombocytopenia;
  • diarrhea, vomit, loss of appetite and as a consequence anorexia, gastralgia, indigestion.

Trimethoprim, instructions for use (Method and dosage)

The drug is prescribed orally. As a rule, it is combined with sulfamethoxazole.

Typically, adults are prescribed from 40 to 60 mg of the drug once a day. Maximum daily dosage = 0.1 grams of substance.

For children, correction of the dosage regimen is required. At the age of one year, 2-3 mg of the drug is used per kg of the child's weight, the frequency of administration is 1 time per day.


There is no evidence of an overdose of the drug.


The combined reception of funds and rifampicin leads to a decrease in efficiency and a reduction in the time of the last removal from the blood.

When combined with other folic antagonists (pyrimethamine, methotrexate) increased risk of development megaloblastic anemia.

Cyclosporin increases the burden on the kidneys.

The bactericidal effect of the drug is enhanced by sulfamethoxazole.

When combining the drug with myelotoxic agentsincreases the likelihood of developing disorders in the work of the bone marrow.

With extreme caution, you need to combine the medicine with dapsone, since this can lead to an increase in plasma concentrations of both drugs and the development of side effects. It is believed that this effect is due to the competition of substances for excretion by the kidneys.

Trimethoprim inhibits renal clearance procainamide, and its active metabolite, their concentration in blood plasma increases significantly.

The substance increases effectiveness warfarinby suppressing its metabolism.

Terms of sale

A prescription may be required to purchase the medicine.

Storage conditions

Tablets are stored in a cool place away from children.

Shelf life

5 years.

Special instructions

With extreme caution, the medicine is used for bronchial asthma, violations in the liver or thyroid gland, in young children.

During treatment, it is recommended to periodically monitor the picture of peripheral blood, monitor the condition of the kidneys and liver.

Elderly patients are recommended to additionally prescribe folic acid.


Treatment of children under the age of one year requires special care.

During pregnancy and lactation

The drug should not be taken by pregnant and lactating women.

Preparations that contain (Trimethoprim Analogs)

This substance is in the preparations: Ipral, Trimethoprim, Trimopan.

Combination Trimethoprim sulfamethoxazole is part of the following medicines: Bactrim, Berlocide, Biseptol, Groseptol, Co-trimoxazole, Oriprim, Sinersul, Sumerolim, Ciplin, Bactrim forte, Brifesptol, Dvaseptol, Metosulfabol, Septrin, Sulotrim, Trimezol, B-Septin, Duo-Sepmet.

Reviews on Trimethoprim

There are few reviews on the use of medicines, which include the substance Trimethoprim. However, no negative messages were found. Combination reviews are much more common. Trimethoprim + Sulfamethoxazole. Medicines with these kind of active ingredients help a lot from cystitis, tonsillitis and even ARVI. Adverse reactions occur with the frequency described in the instructions. In order to avoid complications and to increase the effectiveness of treatment, drugs should be prescribed by your doctor.

Trimethoprim price, where to buy

Buy a drug Biseptol, which contains the substance Trimethoprim, can be about 100 rubles, 20 tablets.

Watch the video: Trimethoprim (December 2019).

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